Sensor specs?

Hey guys,

I'm making a fully digital dashboard with an arduino for my 01 1500, 5.9L, 46RE, 2WD. I need to know the following specs:

VSS pulses per revolution (not per mile, although that might help)
Oil Pressure Sensor voltage specs for PSI (so, what voltage it will output at a given oil pressure)
Water Temp Sensor voltage specs for temperature (just like the Oil Pressure sensor)

That's really all I need. This will save me a LOT of headache. I already have the fuel sending unit's specs figured out, and battery voltage is easy as heck.

Thanks guys.

I may be able to look up those specs for you a bit later.
I see your truck is a 01 so you instrument cluster is on the can bus. How are you going to get around that ?

This is a custom setup, I'm using an arduino so I'm simply tapping into the sensors directly. I'm getting rid of the stock instrument cluster (because, I'm getting rid of the computer soon, lol, going to run FreeEMS or something like that). If you could look those sensor specs up for me, that would be absolutely fantastic.

Your truck will likely not run without the IPC.
Vss is 4k pulse per mile

rowdyram said:

Your truck will likely not run without the IPC.
Vss is 4k pulse per mile

Click to expand...

Well I've ran and driven it just fine with the instrument cluster taken out... Lol. Nothing in the service manual said that the PCM would freak out if there's no cluster.

So that's 4k pulses per mile, with the stock tire size, correct? Now all I need to know is how many times the transmission output shaft rotates per mile (with the stock tires). I have slightly bigger tires so it'd be a good idea to figure out the math for this. That way I'll just put the formula into the code and I can change the tire circumference or whatever if I choose to change tire size again.

About the oil pressure sensor... I've done more research and still can't find anything. So, that leaves me with two options (unless I can get specs). Either put a tee into the inlet, then attach the sensor to that tee, as well as a diagnostic mechanical gauge. From that, I can figure out the specs. Either that, or get a different sensor. Is the oil pressure sensor a 1/8 NPT?

Thanks.
Sam.

Ok ive just ran into a few with failed ipcs that wouldnt start.
4k pulse per mile on odometer. 4kx60 will give you pulses @ 60mph if tgat helps.
Yes it is 1/8 npt
I'm at work now so I'll do some research at lunch

Coolant temp is 244 ohms @90°c +/- 3.7%

Your vss goes to your PCM and is transmitted on the CCD bus to the IPC so you'll have to remove that from the PCM. Your coolant temp is the same deal as well as your o/p sender. I cannot find specs for the o/p.

rowdyram said:

Coolant temp is 244 ohms @90°c +/- 3.7%

Click to expand...

Do you know what the other resistance ratings would be for this? Like, a range? 244 ohms at 90C does help but it'd be nice to know what kind of resistance it'd have at say, 20C.. that way I can get a range and know what it'll do at different temps. Also, it's alright you can't find the oil pressure specs, I'm really happy with what you've got me so far haha. Thank you.

Keep in mind though, I'm measuring voltage, not resistance. So for instance, the fuel sender is 20 ohms when full and 220 ohms when empty. The service manual states that a constant current source of 32ma is supplied to the sensor, which, using ohms law, equates to 7 volts when empty and 0.7 volts when full. Which, is exactly what the service manual states. If you know of what the specified current sent to the water temp sensor is, let me know. Otherwise, I believe it'd be pretty easy to figure out, I just need to grab a multimeter. I do know that the input voltage to the water temp sensor is 5 volts, it is grounded to the engine block, so one wire is the input signal, which uses a regulated current, and the other wire is the output signal, which will vary in voltage. The arduino is simply measuring voltage. I have no need to disconnect these sensors from the ECU for the time being, I'm just going to tap into the wires and measure the signal with the arduino just like I would with a multimeter. According to the manual, about the water temp sensor, it states "resistance (voltage) in the
sensor decreases. As temperature decreases, resistance
(voltage) in the sensor increases."

Basically, above all, I need to know two different data points, so a low temp, and what the resistance for that is, and then like you just stated, a high temp (so, 90C). Thanks a ton for the VSS specs, by the way, that's a life saver right there. That was the most important thing to figure out since I need to have an odometer haha

If you can't find that, would you suggest I leave the engine off long enough to let the coolant reach ambient temp, and measure the resistance from the sensor then?

Sorry, haven't been on in a while. But yes the best way to do it would be to measure resistance as it warms using a ir temp gun on the sensor and graph it. Or back probe the connector measuring voltage drop and use ohms law to calculate

rowdyram said:

Sorry, haven't been on in a while. But yes the best way to do it would be to measure resistance as it warms using a ir temp gun on the sensor and graph it. Or back probe the connector measuring voltage drop and use ohms law to calculate

Click to expand...

So where would be the best spot to point the thermometer? Thank you so much for the help.

As close to the sensor base as possible

So the engine's metal by where the sensor is is going to be close enough to the coolant temp to be accurate?

That should be fine

hey Sam why did you decide not to use the mega squirt set up?

MoparMagic'00 said:

hey Sam why did you decide not to use the mega squirt set up?

Click to expand...

Price, and the fact that I really don't want to support them since it isn't open source. I'm going with either FreeEMS or rusEFI now, both highly experimental open source ECU systems. I'd rather be a guinea pig and spend a while solving bugs than spend a ton of money supporting a closed source project. Megasquirt has its own set of actual issues too.

By the way, I rebuilt my transmission over spring break. It's doing really well, I believe I'm ready to start designing a standalone controller for it. Chirps the tires during a WOT 1-2 shift, and shifts so fast that the accessory belt squeaks. lol.

rowdyram said:

4k pulse per mile on odometer. 4kx60 will give you pulses @ 60mph if tgat helps.

Click to expand...

Are the VSS and Output Shaft Speed Sensor on the transmission two separate things? The annulus gear in the overdrive has 23 teeth on it that the output shaft speed sensor senses moving. It's a halls effect thing. The manual says this:

"Speed sensor signals are triggered by the park
gear lugs as they rotate past the sensor pickup face.
Input signals from the sensor are sent to the transmission
control module for processing. Signals from
this sensor are shared with the powertrain control
module."

If that's true, I have no clue how 4k pulses per mile would make any sense for this sucker. If there's 23 teeth it passes over, I figure that means there's 23 pulses per every output shaft rotation. If that's true, then it should be doing around 52k pulses per mile (Around 2262 rotations of the output shaft per mile).

The oss is for trans control only the vss in the t case is for speed control.
The vss is a sign wave... So intensity will increase with speed but 4k is what prodemand says